European students have been cutting classes, marching to protest the lack of action on climate change. In Belgium, the demonstrations are in their seventh week. Teri Schultz reports from Brussels.

TERI SCHULTZ, BYLINE: Like usual on school mornings, Toon Lambrecht is running late, and his mother is telling him to hurry. But getting ready on Thursdays has been unusual the last few weeks.

SCHULTZ: OK. So you took out all your schoolbooks.

TOON LAMBRECHT: Yeah, indeed. I need my stuff to go to the march.

SCHULTZ: The 16-year-old Lambrecht is one of the organizers of Brussels students' strikes demanding climate action, weekly walkouts aimed at provoking parents, principals and politicians into urgently addressing environmental destruction. Waiting for his train into Brussels for the march, Lambrecht admits he's pleasantly surprised at how the movement has spread. The protests started in Sweden. And in recent weeks, students in Germany, France, the UK and even Australia have joined in. Some of the biggest demonstrations have been here in Brussels.

LAMBRECHT: We didn't believe that, but I think this only shows that all the youth is worried about their future and that we want change.

SCHULTZ: Lambrecht is lucky. Both his parents and his principal support his participation. His fellow organizer Gilles Vandaele faces retaliation both at school, where administrators threatened to make him repeat his senior year, and at home, where his grandmother says she won't visit him again until he stops protesting. Vandaele says he understands his grandparents think school is important.

GILLES VANDAELE: But it does hurt my feelings when they refuse to see how important this is. And also, when they see that I get to stand in front of the European Parliament and they don't see the educational value in that, I think that's a shame. I think that's pretty short-sighted.

SCHULTZ: Still, Vandaele says, whatever punishment he gets is worth it, especially this week when he stood alongside the founder of the student climate strikes, Swedish teen Greta Thunberg. She made headlines recently in Davos, where she lectured world leaders on the need to address the climate issue. In Brussels, she told European Union officials it was time for them to take action.

(SOUNDBITE OF ARCHIVED RECORDING)

GRETA THUNBERG: We need to protect the biosphere, the air, the oceans, the soil, the forests. This may sound very naive, but if you have done your homework, then you know that we don't have any other choice. We need to focus every inch of our being on climate change.

SCHULTZ: In the audience was European Commission President Jean-Claude Juncker, who praised the movement, although he noted in his day, students protested outside school hours.

(SOUNDBITE OF ARCHIVED RECORDING)

JEAN-CLAUDE JUNCKER: (Through interpreter) I'm glad to see that young people are taking to the streets in Europe to raise the issue of climate change. But mitigating it is not just a job for young people, but also for older people, if only they'd take up the task.

SCHULTZ: Juncker said a quarter of the next EU budget that takes effect in 2021 will be spent on action to mitigate climate change. But the taciturn Greta Thunberg was not impressed. She was asked whether she'd heard anything in Brussels that made her optimistic.

(SOUNDBITE OF ARCHIVED RECORDING)

THUNBERG: No.

SCHULTZ: Nearly 10,000 students, their parents and grandparents took part in Thursday's rally in Brussels. Today, Thunberg and some of the leaders of the Belgian movement will be joining French protesters in Paris. For NPR News, I'm Teri Schultz in Brussels. Transcript provided by NPR, Copyright NPR.